Grinding-machine



B. M. w. HANSON. GRINDING MACHINE.

' APPLICATION FILED DEC. 6,1919.

Patented Aug. 23, 1921.

2 SHEETS-SHEET 1.

3144mm tor,

BEG-'1.- M. W. HANSON, 0F HARTFORD, CONIN'IEC'J.IiC'lIT'JJ.

GRINDING-MACHINE.

Y Specification of Letters Patent.

Patented Aug. 23, 1921.

Application 'flledi'beceniber 6,1919. Serial No. 342,912.

To all whom it may concern:

Be it known that I, BENGT M. W. HAN- SON, a citizen of the'United-States, and a resident of Hartford, county of Hartford,

State of Connecticut, have invented certain new and useful "Improvementsin Grinding- Machines, of which the following is a specification.-

The purpose of this invention is to so organize the parts of a grindingmachine that finish grinding operations may be carried out with thegreatest accuracy so that the work when it comes from the machine,

will be in condition for use without the news sity of any furtherfinishing operations.

This result is obtained by a proper sup-port of the moving parts so thatthey will always be maintained in proper position and relagtion to oneanother. This is of particular importance in certain classes of work,such for instance as the grinding of ball races, the embodiment of theinvention which is here selected for illustration and description, forin such cases the ball race itself must be rotated on its own axis so asto present the full circumference of the raceto the action of thegrinding wheel which rotates and the race must also be rocked oroscillated across the grinding wheel so that the full width of the racewill be presented to the wheel. These movements of the race, which arebrought about by suitable mechanism, must be smooth and regular and freefrom any vibration or other-1nfiuences tending to give an irregularmotion which might-result from the driving mecha. nism which actuatesthe holder for the ball race. A further object of the invention is toprovide a machine with certain adjustments in order that it may beadapted to different classes of work; for instance, the grinding ofdifferent type of ball races. It is to be understood that while theinvention is illustrated and described as incorporated in a machine forgrinding ball races, it is adapted for other work.

In the drawings I Figure 1 is a side elevation of so much of a grindingmachine'as is necessary to illustrate the invention, some parts beingshown in section. l

Fig. 2is a plan view of the work holder, partly shown in section.

Fig. 3 is a igiew similar to Fig. 2 but with the parts adjusted foroperation on a different type of race from that shown in Fig. 2.

Fig. 4 is a plan view taken substantially on the line 4-4 of Fig. 1showing the oscillating means for the work holder, and

Fig. 5 is a sectional plan view on the line 5-5 of Fig. 1.

Referring to the drawings, a denotes what may be considered the frame ofthe machine on which is mounted a carriage b for the support of thegrinding wheel shaft 0, the grinding wheel being indicated at d. Thecarriage b, of any suitable construction, may

be adjusted upon the frame in any desired manner, nospecific means foraccomplishing this result being shown, as the particular constructionthereof is immaterial. e denotes generally the work holder mechanismwhich is mounted at the top of, a vertical shaft 7 which has on itslower end a segment gear 9 meshing with a corresponding segment gear hon a crank lever Z connected by a link m to an eccentric a driven in anysuitable manner.

The complete work holder e is supported in the following manner. Mountedon the frame of the machine is an upstandin conical bearing member 5.Fitting onto this upstanding conical bearing member 5 is a complementaryconically recessed bearing member 6 and this bearing member 6 carriesthe work holder e and is attached to the shaft 7. In the upper part ofthe work holder 0 is a conical recess to receive a conical steadyingbearing 7 carried in a fixed part8 of the machine. a i

- By reference to Figs. 2 and 3, it will be seen that it is necessary tooscillate the work holder in a horizontal plane in order to present thefull width of the groove of the race to the grinding wheel and thisoscillation is brought'about by an oscillating move-' ment of the shaftf which-is secured in the -manner hereinabove set forth through theeccentric 1, link we and segmental gears .g, h.

In order to insure that the work holder shall have a smooth and regularoscillation, free from vibration incident to the actuation of the shaftf, this shaft is made in three sections, 10, 10? and 10". lhe lowersection 10 is mounted in a long bearing 11 on the frame of the machine.The upper section 10 is connected with the recessed conical bearingmember 6 as hereinabove set forth. The intermediate section 10 is notsupported in bearings on the machine frame but is connected at its upperand lower ends to the upper and lower sections in the following manlarlyof too nor. At the upper end of the lower section radial arms 18corresponding in number to the radial arms of the sleeve 15.

By reference to Fig. 5, it will be seen that the radial arms at theadjacent ends of the shaft sections are staggered with relation to oneanother and between and connected to these radial arms there ispositioned a fiexible disk 20. @f course, there is a similar connectionbetween each end of the intermediate shaft section and. the adjacentends of the upper and lower shaft sections. lit will be apparent thatwhile these flexible connec tions will transmit the rotary motion fromone shaft section another,- any flexure or distortion of one shaftmember and particul lower section which directly re" ceives the drivingimpulse will not be transmitted to the other shaft sections. suit isthat any cramping of the lower shaft section in its beariior any wearofthe hearing which might allow for play will not transmitted through theintermediate shaft section and the flexible connections or couplings tothe upper shaft section and so the work holder and since this workholder is supported on a bearing of liberal size and is accuratelycentered and steadied by the top bearing, a smooth and regular movementof the work holder is insured, This means that as the work holder isoscillated to move the race across the wheel, an accurate and smootnnished surface is produced, free from any unevenness which would resultif means were not employed for dampening or eliminating the vibration ofthe work holder.

It is, of course, apparent that in grinding a ball race, the oscillatingmotion shall talze place about that center from which the'transversecurve of the race is originated. in the case of the race shown in Fig.2, the trans verse curve of the race is struck from the center of thebearing and, consequently, the chuck which holds the bearing must be soadjusted on the work holder that the center of the transverse curvatureof the hearing shall be coincident with the axis of the shaft or moreproperly the axes of the alined bearings 5 and 8. ln the case of theball race shown in Fig. 3, where the transverse curvature of the race isstruck from the corn ter 2:, indicated by the cross lines, the chuck inwhich the race is mounted must be moved so that this center shall becoincident with the axis of the bearing 5. In order to provide for suchadjustments'of the chuck to make the machine of more or less universalThe re 3 applicability, the chuck 30 is mounted in a carrier 31 whichslides on a gib '82 on the work holder head 33, a clamp 34; beingprovided to secure this carrier in any position of adjustment. The chuckspindle has a pulley 35 to receive a driving belt. It is of courseunderstood that after the carrier 31 is properly adjusted, the carriagei) is adjusted to bring the grinding wheel into enga ement with therace.

nile the form of the device herein shown and described is admirablyadapted to fulfil the objects of the invention, it is to be understoodthat it is not intended to confine the invention to this embodiment, asit is susceptible of embodiment in various forms all coming within thescope of the claims which follow.

I claim as my invention 3- l. in a grinding m chine, an oscillating workholder, a bearing supporting said holder, oscillating mechanism, andflexible shaft forming a connection between work holder andoscillatingmechanism.

2. i. a grinding machine, an oscillating work holder, a bearingsupporting said worlr holder, oscillating means, a shaft extendingthrough hearing and forming COHI16C- tion between said holder andoscillating mechanism, said having a section connected to said osci-llamechanism, a section connected to said work holder, an intermediatesection there-between and flexible connections between said sections,and a bearing for supporting the first mentioned section.

3. a grinding machine, an oscillating" work holder, a foot bearing andan overhead bearing supporting work ler, oscillating mechanism, a...flexible forno= 7 inga connection between said work l'ioldcr andoscillating mechanism.

61-. in a finding raachine, oscillating head, a carrier adjustable onsaid head transversely to the of oscil ation there in said carof, achuck rotatably mounted rier, a foot bearing an overhead bearing betweenwhich oscillating head is supported.

5. in a grinding machine, an oscillating head, a foot bearing and anoverhead bear ing between which said head is supported, a carrieradjustable on head right gles to the axis about which the'sa'nieoscillates, a chuck rotatably mounted in said connected alined sectionswith the upper section extending through said bearing and connected tosaid holder.

7. In a grinding machine, an oscillating Work holder, a foot bearing andan 'overhead bearing supporting said Work holder, a shaft comprising aplurality of flexibly connectedalined sections with the upper sectionextending through said foot bearing and connected to said holder, andoscillating mechanism connected to said shaft.

8. In a grinding machine, an oscillating head, a chuck rotatably mountedon said head, a foot bearing and an overhead bearing between which saidoscillating head is supported.

9. In a grinding machine, an oscillating head, a foot bearing and anoverhead bearing between which said head is supported, a chuck rotatablymounted in said head, a grinding wheel relatively adjustable at rightangles to the axis about which the head oscillates, oscillating means,and a flexible shaft forming a connection between said oscillating meansand head.

BENGT M. W. HANSON.

